The invention relates to a cuff for connecting to an equipment, which can in particular be a pipe.
It can be used for ensuring the continuity of two equipments provided with conduits locating substantially in extension of one another, but at the mouths separated by a certain distance and permitting the circulation of a fluid or other content from one conduit to the other. Therefore such a cuff must comprise a tube, whose ends are fitted to the mouths of the conduits and means for fixing or clamping the ends of the tube to the respective conduits.
The respective position and orientation of the equipments must be defined with great precision in order that the connection or coupling offered by the cuff is perfectly tight, even if there is a certain latitude as a result of the possibility of interposing elastic joints or bellows, crushed to a greater or lesser force as a function of the clearances encountered, between the mouths of the conduits and the ends of the tube. These problems are complicated when the mouths are liable to be mutually displaced with time or when a direct manipulation of the cuff is impossible, which is the case when it is located in a hostile environment where remote manipulation is indispensable. However, such manipulations are necessary for periodically replacing the joints or the cuffs.
A tube cuff is known formed by at least one rigid section and whereof FIG. 1 shows one end, the other being symmetrical. A tube 1 of the cuff is connected by its end to a pipe 2 equipped with a clamp 3 extending in front of its mouth 4. The clamp 3 has an opening 5 in front of the mouth 4 and which extends level with the clamp 3, forming a cuff introduction or dismantling passage 6. The clamp 3 forms with a collar 7 around the mouth 4 and connecting, intermediate flanks 8 (whereof only one is shown) a receptacle 9 open at its top and into which is introduced one of the ends 10 of the tube 1 and one of the ends (equipped with a collar 15) of the cuff 12, which are then placed on the bottom of the opening 5, whilst being pressed against the mouth 4, accompanied by the interposing of a sealing O-ring 11 (provided with a gripping tongue permitting easy positioning).
A sleeve 12 placed round the tube 1 and permitting the fastening of the end 10 also passes through the opening 5. The collar 15 established at its end located in the receptacle 9 then approaches the inner face 16 of the clamp 3, oriented towards the mouth 4, until it touches said inner face 16. Once the collar 15 is wedged by means of the washer 17 on the inner face 16 of the clamp 5 by imposing thereon a rotation about its axis, the rotation of the sleeve 12 brings about the translation of the tube 1, whose end 20 fixes the joint 11 on the pipe 4. The sleeve 12 is turned by a capstan 18 fixed to its outer periphery and which can be actuated by a not shown, specialized machine and it is possible to fix a remote manipulator. The tube 1 can be provided with an anti-torque positioning plate 19 not far from the sleeve 12 in order to prevent it from turning during screwing and unscrewing. A washer 17 is intercalated and fixed between the clamp 3 and the collar 15. Its faces directed towards said two parts have shapes complimentary of the faces against which they are intended to bear, so as to bring about a stable bearing on a large surface. The mutual bearing faces of the collar 15 and the washer 17 are spherical in order to compensate the lack of parallelism of the sleeve 12 with the tube 2 during putting into place. However, with said cuff, it is relatively difficult to regulate the fixing force, which is dependent on the characteristics of the specialized machine and the friction in the thread 14 and between the collar 15, washer 17 and inner face 16. Moreover, the transmission efficiency by meshing between the capstan 18 and the specialized machine is mediocre. The fixing or fastening effect stops as soon as the specialized machine has to apply a rotary torque exceeding that for which it has been set, no matter what the position obtained. The thread 14 can also give rise to jamming phenomena, which would make the cuff very difficult to dismantle. Finally, it is difficult to ensure that the washer 17 remains correctly positioned during installation, because the rotation of the collar 15 can lead to movement thereof even in the upwards direction despite the precautions taken, so that the end 10 of the tube 1 will no longer be appropriately matched with the mouth. These failure possibilities with respect to fitting or dismantling make the cuffs of FIG. 1 inadequate. Another of their disadvantages is their excessive rigidity, which prevents them from adapting to the movements of the pipes 2 and in particular to the rotary displacement movements of the axis of the tube 1 relative to the axis of the pipe 2. The border 20 of the end 10 of the tube 1, which bears on the O-ring 11, is given a spherical shape in order to maintain the sealing action if the end 10 rotated with respect to the mouth 4, but the nature of the connection between the tube 1 and the pipe 2, particularly at the location of the washer 17, does not make it possible to ensure that such a rotary movement is in fact obtained. The O-ring 11 may become inadequate for producing the desired sealing action.